Terminal insertion apparatus



United States Patent I 1 3,545,662

[72] Inventor Willard Le Roy Busler Primary Examiner-Granville Y.Custer, Jr.

Harrisburg, Pennsylvania AttrneysCurtis, Morris and Safford, Marshall M.[21 Appl. No. 724,422 Holcombe, William Hintze, William J. Keating,Frederick [22] Filed April 26, 1968 W. Raring, John R. Hopkins. Adria J.LaRue and Jay L. [45] Patented Dec. 8, 1970 Seitchik [73] Assignee AMPIncorporated Harrisburg, Pennsylvania 54] TERMINAL INSERTION APPARATUSABSTRACT: Terminal insertion apparatus for inserting Claims, DrawingFigs boxlike terminals into printed circuit boards has strip feedingmeans for feeding a continuous strip of end-to-end terminals [52] US. Cl227/95 towards h Surface of the board Leading terminal of Strip is 1327f7/00 severed from the strip at a location above the surface of the Fieldof Search 227/77.93, board and gripped by an insertion Slide whichcarries the minal downwardly and inserts it through an opening in theReferences Cited board. Thereafter, legs of this leading terminal, whichextend through the board, are bent outwardly to lock the terminal inUNITED STATES PATENTS place. Towards the end of the operating cycle,severing 883,862 4/1908 Cummings 227/95 blades, which are movablelaterally towards each other and 1,958,438 5/1934 LaChapelle 227/93Xtowards the strip of terminals, move inwardly and sever the 2,947,9908/1960 OKelley 227/95 next adjacent terminal from the strip. This nextadjacent ter- 3,134,982 6/1964 Gagnon et al.. 227/93X minal is picked upby the inserting means and carried to the 3,346,162 10/1967 DeShong227/95 board during the next succeeding operating cycle.

PATENTED DEC 8 19m SHEEI 1 OF 9 PATENTED DEC 81970 SHEET 5 OF 9 PATENIEDnan 81970 SHEET 7 [1F 9 PATENIED 05a 8 19m SHEET 8 OF 9 TERMINALINSERTION APPARATUS BACKGROUND OF THE INVENTION This invention relatesto apparatus for inserting contact terminals into printed circuit boardsor the like. The invention is particularly intended for use in theconsumer electronics industry, for example, in the manufacture oftelevision sets, where relatively complex printed circuit boards must beproduced in large numbers at a very low cost. The production machineryof such boards requires devices for rapidly inserting terminals of hevarious types needed into the boards as they move past applicatorsmounted beside the assembly line. A high degree of reliability isrequired of such applicators for the reason, among others, that thefailure of a single applicator requires that an entire production linebe shut down with resulting idling of all of the other applicators andother assembly machinery on the production line.

An object of the invention is to provide an improved inserting apparatusfor inserting contact terminals into the printed circuit boards. Afurther object is to provide an apparatus which has an extremely shortcycling time and can, therefore, insert an individual terminal into aboard during a very short time interval. A further object is to providea highly reliable apparatus capable of operation for an extended periodwithout substantial servicing or other maintenance. A still furtherobject is to providean apparatus which is capable of performing a finalforming operation on a terminal immediately prior to inserting theterminal into a printed circuit board.

These and other objects of the invention are achieved in a preferredembodiment thereof comprising an apparatus having a strip-feeding meansfor feeding a continuous strip of endto-end connected contact terminalstowards a printed circuit board. The end portion of the strip is fed toa location immediately above the opening in the board into which a terminal is to be inserted and the leading terminal of the strip is severedfrom the strip during the final portion of an operating cycle. At thebeginning of the next operating cycle, an inserting slide carries thepreviously severed terminal downwardly, and inserts it through anopening in the printed circuit board. While the leading terminal isbeing inserted into the board, the strip of terminals is fed a distanceequal to the length of a single terminal so that the next adjacentterminal is located at the end of the strip feed path. Thereafter, theinsertion slide returns to its starting position and grips this nextadjacent terminal in preparation for the next operating cycle.

In the drawings:

FIG. 1 is a sectional side view of a terminal applicator in accordancewith the invention, this view showing the positions of the parts whenthe insertion slide is in its elevated position at the beginning of theoperating cycle and being taken along the lines l-l ofFIGS. 4 and 5;

FIG. 2 is a view similar to FIG. 1 but showing the positions of theparts at an intermediate stage of an operating cycle and after aterminal has been inserted into a printed circuit board;

FIG. 3 is a view taken along the lines 3-3 of FIG. 1 and again showingthe positions of the parts at the beginning of an operating cycle;

FIG. 3A is a view similarto FIG. 3 but showing the positions of theparts at the intermediate stage of FIG. 2;

FIG. 3B is a fragmentary view showing details of the strip feed slide; J

FIGS. 4 and 5 are views taken along the lines 4-4 of FIG. 2 and 5-5 ofFIG. 1 respectively;

FIG. 6 is a fragmentary view on an enlarged scale taken along the lines6-6 of FIG. 1 and showing the relationships of the severing blades andthe insertion slide to each other at the beginning of the operatingcycle;

FIGS. 7 and 8 are views similar to FIG. 6 but showing the positions ofthe parts at successive stages of the operating cycle;

FIG. 9 is a view taken along the lines 9-9 of FIG. 6;

FIG. 10 is a view similar to FIG. 9 but showing the positions of theparts after insertion of the terminal into the printed circuit board;

FIG. 11 is a fragmentary perspective view showing the end portion of theinsertion slide with the parts exploded from each other in the interestof clarity;

FIG. 12 is a fragmentary perspective view showing the lower portions ofthe insertion slide and associated structure; and

FIG. 13 is a descriptive timing diagram showing the relative movementsof the parts during a complete operating cycle.

Referring first to FIGS. 6 and 10, the disclosed embodiment of theinvention is adapted to insert terminals 202 which are manufactured inthe form of end-to-end terminal strip 200, each terminal being axiallyalined with the next adjacent terminal of the strip and integraltherewith. The individual terminals comprise a pair of spaced apartgenerally rectangular boxlike section 204, 206 which are connected toeach other on two opposite sides by integral straps 208, 210. Contactsprings 212, are integral with the lower box section 206 and extenddiagonally, with respect to the axis of the terminal, towards eachother. A pair of legs 214, 216 extend downwardly as viewed in thedrawings from the lower box section and are adapted to be insertedthrough the opening in the printed circuit board. After such insertion,these legs are bent outwardly to hold the terminal in place until it issoldered to the board. After the terminal has been secured to the board,it is adapted to receive a blade contact having a rectangular crosssection which is inserted between the springs 212 to establishelectrical contacts therewith. Terminals of the particular type as shownin FIGS. 6-10 are more fully described in U.S. Pat. No. 3,270,251. Itwill be understood that the principles of the invention can be adaptedto the insertion of terminals other than the specific terminal shown inthe drawing.

Referring now to FIGS. 1-5, an applicator 2 in accordance with theinvention is adapted to be mounted on the end of an arm 4 of a suitableframe above the surface of the printed circuit board 6. It will beunderstood that the board 6 will normally be mounted on a suitableconveyor and that during each operating cycle, a single terminal will beinserted into the board and the conveyor will then be indexed toposition another printed circuit board under the applicator. The frameon which the applicator is mounted may be a conventional C- type pressframe as disclosed, for example, in U.S. Pat. application Ser. No.717,086, filed Mar. 29, 1968, by Willard L. Busler et al.

The applicator 2 comprises a generally L-shaped frame casting 8 (FIG. 5)secured to the end of the arm 4 and having sides 10, 12. Arm 10 has anupwardly projecting extension 11, shown fragmentarily in FIGS. 1 and 2,on which an air cylinder, referred to below, is mounted. An L-shapedbracket 14 is mounted on one side of the arm 12 and a gib 18 is mountedon this bracket. A complementary gib 16 is mounted on the arm 10, thesegibs functioning as guides for a generally channel-shaped main driveslide 20 which reciprocates vertically during the operating cycle. Themain drive slide has a web portion 22 and a pair of opposed arms orsidewalls 24, 26, the outer surface of which are grooved to receive thegibs.

The main drive slide 20 is moved downwardly then upwardly during anoperating cycle by means of a piston rod 28 extending froma suitablepiston-cylinder (not shown) having a clevis 30 threaded to its end. Theclevis 30 has a slot 29 on its rightwardly facing side as viewed inFIG. 1. A plate 32 is received in this slot and supported by an arm 31on the lower end of the clevis. Plate 32 extends across the upper endsof, and is secured to, the arms or sides 24, 26 of the main drive slideby fasteners 34 (FIG. 4).

An insertion drive slide 36 is slidably mounted between the arms 24, 26of the main drive slide and has a rightwardly facing groove 38 (asviewed in FIG. 5) extending centrally along its exposed side. Aninsertion slide assembly 40 (FIG. I), having a rectangular cross sectionis mounted in this groove and carries, on its lower end, the grippingmeans for gripping the terminal being inserted into the printed circuitboard as will be described subsequently. This insertion slide assembly40 is keyed to the insertion drive slide 36 in a manner described below.Insertion slide 36 is normally biased upwardly as viewed in the drawingby means of a pair of coil springs 42 which extend through holes in theinsertion slide. The upper ends of these springs are connected to pins44 in the plate 32 (FIG. 4) and the lower ends of the springs areconnected to pins 46 mounted in the lower end of the insertion driveslide. Upward movement of the insertion drive slide beyond the positionshown in FIG. 1 is prevented by means of a rod 48 which extends throughan opening in the plate 32 and is secured in an opening in the insertionslide 36 by a setscrew 41, see HO. 4. The upper end of this rod 48 isadapted to bear against the end of a setscrew 50 mounted in a fixedbracket 52 secured to the extension 11 of the frame wall 10.

The insertion slide 40 is yieldably coupled to the insertion drive slide36 by means ofa spool 54 which is contained in an opening 68 in thelower end in the lower portion of the insertion drive slide 36. Spool 54has a circumferential recess 56 intermediate its ends which receives alaterally extending boss 58 on the lower end portion of the insertionslide assembly 40. The spool 40 is slidably mounted on a rod 60 which isthreaded at 64 into the lower end 62 of the insertion drive slide andwhich extends upwardly through opening 68 and into a drilled hole 66 inthe insertion drive slide at the upper end of the opening 68. A coilspring 70 surrounds the rod 60 and bears against the upper surface ofspool 54 and against the insertion drive slide 36 at the upper end ofopening 68. As explained immediately below, this coupling arrangementpermits overtravel of insertion drive slide 36 with respect to insertionslide assembly 40 and thereby protects the printed circuit board intowhich terminals are being driven against damage.

It will be apparent from FIG. 1 that the spool 54 is spring loadeddownwardly by the spring 70 and that downward thrust is transmitted fromthe insertion drive slide 36 through the spring 70 and spool 54 to theboss 58 on the insertion slide 40. It should be mentioned that thespring 70 is relatively a stiff spring and will be compressed only if asubstantial resistance presented to the spool 54 during downwardmovement thereof. By virtue of this arrangement, if the insertion slideassembly 40 reaches the lower limit of its travel and fully inserts theterminal through a printed circuit board before the insertion driveslide 36 has reached the lower limit of its travel, the insertion slideassembly will cease to move downwardly and there will be a slightlycompression of the spring 70 with concomitant downward movement of theinsertion drive slide relative to the spool 54. This arrangementprevents damage to the printed circuit board or the terminal if theterminal should be fully inserted before the end of the downward strokeof the drive slide and thereby permits the applicator to be used onprinted circuit boards of varying thicknesses.

A cylindrical rod 74 is pinned or otherwise secured in the laterallyextending car 72 on the insertion slide 40. This rod, 74, extendsdownwardly through a drilled opening 76 in a plate member 78 securedintermediate the ends of a generally channel-shaped frame piece 80,which, in turn, is secured to the wall of the casting by fasteningmeans. The terminal strip 200 is fed downwardly through the plate number78 through a slot 84 therein and towards the lower end of the insertionslide 40 as will be described below.

The insertion slide 40 has an extension 86 on its lower end, whichprojects diagonally towards the feed path of the terminal strip, and adepending arm portion 88 which extends parallel to the feed path. Therod 74, has a generally l-i-shaped block 90 on its lower end (FIG. 12)having a recess 92 on its left-hand side as viewed in the drawing. Thisrecess accommodates the lower portion of the insertion slide member 40and the extension 86 thereon. The recess 94 on the opposite side of theblock 90 receives an extension 96 of the plate member 78 and has a latchblock 100 mounted therein. A latch arm 98 is pivotally secured at 102 ina recess in the block 100 and a spring 104 interposed between the blockand the latch arm normally biases the lower end portion 101 of thislatch arm towards the arm portion 88 of the extension 86 of theinsertion slide. A set screw 106 is mounted in the upper end of theblock 100 to control the movement of the lower end of the latch arm 98so that it will effectively grip the leading terminal of the stripduring insertion as will be described below. The plate member 78 is cutaway on its lower side as shown at 108 to accommodate the right handportion of the block and the latching block structure as shown best inFIG. 1. The right hand surface of the block 100 bear against a bearingsurface of a plate 110 secured to the frame extension 80 and guides thelower end of the insertion slide and the terminal gripping means mountedthereon along a straight line path towards and away from the printedcircuit board.

Turning now to FlGS. 61 1, the rightwardly facing surface 116 of the endportion 88 of the insertion slide member 40 has a pair of spaced-apartrightwardly extending flanges 118 which are adapted to grip the leadingterminal of the strip as shown in FIG. 6. immediately above theseflanges, a pair of spaced-apart bosses 120 are provided which havesurfaces sloping inwardly towards the feed path and towards each otherthereby to guide the strip downwardly as viewed in FlG. 6 during thefeeding operation. The end portion 122 of the latch arm 98 has aleftwardly extending boss 124 which lodges between the box portions ofthe leading terminal and serves to hold this terminal in position whenthe insertion slide moves relatively towards the printed circuit board.

During the final portion of the operating cycle, the leading terminal ofthe continuous terminal strip is severed from the strip by means ofapair of severing blades 126, 128 which are slidably mounted in channels130 in blocks 132. The guide blocks 132 are secured to the surface ofthe lower end of the frame member 80 by fasteners 133 so that theyremain stationary during downward movement of the insertion assembly.Each blade 126, 128 is provided with a pin 138 intermediate its endswhich receives the notched lower ends of a pair of spaced-apart levers140 mounted on opposite sides of the strip feed path. These levers arepivoted intermediate their ends at 142 in blocks 144 which are alsosecured to the frame member 80. The upper ends 146 of the levers areprovided with cam followers 148 which extend into cam slots 150 inplates 152. The plates 152 are mounted on the arms 24, 26 of the mainpower slide 20 so that they move upwardly and downwardly relative to thecam followers 148 during the operating cycle. The contours of the slots150 are such that the severing blades are in their closed condition atthe beginning of the operating cycle and dwell in their closed conditionduring the initial stages of downward movement of the main drive slide20. The blades move relatively apart as shown in the timing diagram anddwell in their open position (FIG. 3A) while the inserting operation isbeing carried out and during a portion of the return stroke of the maindrive slide. The blades are closed during the final portion of theupward stroke of the drive slide and sever the previously fed terminalfrom the strip so that it can be picked up and carried downwardly duringthe succeeding operating cycle by the insertion slide assembly. Itshould be mentioned that the blocks 144 on which the levers 140 aremounted are advantageously adjustable by means of adjusting screws 154in order to precisely sever and form the terminal.

The terminal strip is fed a distance equal to the length of a singleterminal while the inserting operation is being carried out by means ofa strip feed pawl pivotally mounted at 162 in a recess 166 of a stripfeed slide 168. The strip feed slide, in turn, is slidably mounted in arecess 170 in a block 172 which is secured against one side of the plate78 by fasteners 171 (FIG. 1 and 5). The end portion of the feed pawlextends through an opening 164 in the plate member 78 and engages theforth terminal from the end of the strip immediately adjacent to itsforward box section. A spring 169 mounted on the feed slide biases thefeed pawl into engagement with the strip. Feed slide 168 is normallybiased upwardly by a spring 178 contained in a drilled opening in thefeed slide. This spring bears at its lower end against a pin 174 fixedin the block 172 and at its upper end against a cap member 180 whichcloses the opening in which the spring is contained. The pin 174 extendsthrough aligned slots 175 in the feed slide and is, therefore, fixedwith respect to the slide. Feeding is accomplished by means ofa setscrew 179 mounted on the clevis 30. Upon downward movement of the mainpower slide 20, this set screw engages an ear 181 which extends from thefeed slide and drives the slide through its feeding stroke, the returnof the feed slide being effected by the spring 178.

It is desirable to be able to feed the terminal strip through a singlefeeding stroke manually while the applicator is being adjusted orserviced. Manual feeding of the strip in the disclosed embodiment can beeffected by a plunger 183 which is slidably mounted in an externallythreaded bushing 184. This bushing, in turn, is mounted in a bracket 186secured to the side of the plate 78 above the block 172. The plunger ismerely pressed down until it engages the cap piece 80 in order to feedthe strip.

During retraction of the feed slide and during movement of the feed pawl160 over the strip, retractile movement of the strip is prevented bymeans of a stop pawl 188 mounted in an opening in a block 192 on theopposite side of the plate 78 from the side on which the feed mechanismis mounted. The end portion of this stop pawl extends through an opening190 in the wall of the plate member 78 to permit the pawl to engage thestrip. The pawl is normally biased into engagement with the strip bymeans ofa spring as shown in FIG. 3, an arrangement which permitsdownward movement of the strip during downward movement of the feedslide but prevents upward movement of the strip during the return of thefeed slide.

When a new strip of terminals is being inserted through the passageway84, or when the strip of terminals is being removed from thispassageway, it is desirable to disengage the feed pawl 160 and the stoppawl 188 from the strip. In the disclosed embodiment, this isaccomplished by a cam 185 contained in a recess 191 in the plate 78. Cam185 is secured to the end of a shaft 187 that extends beyond the surfaceof the plate 78 and has a knob 189 on its end so that the cam can berotated from its normal position. Upon such rotation of the cam, itengages pins 193, 195 in the stop pawl and feed pawl and moves thesemembers away from the strip so that the strip can be inserted orwithdrawn from the strip feed passageway.

After the insertion of a terminal through an opening in the printedcircuit board, the legs 214, 216 of the terminal are bent outwardly by apair of normally closed spreading fingers 194. These fingers aredisposed beneath, and in alignment with, the opening in the printedcircuit board so that when the terminal is inserted, the legs will be onthe opposite sides of the fingers. The fingers are then moved apart tobend the legs laterally as shown in FIG. 8 and secure the terminaltemporarily to the board until it is soldered. The mechanism forspreading these fingers may be, for example, of the type shown in U.S.Pat. No. 3,293,735 or of any other desired type. It is only necessarythat these fingers move apart after the insertion operation has beencompleted.

A suitable drag mechanism is provided on the strip in the form of ablock 195 mounted in a suitable recess in the plate 78 and biasedtowards the strip by springs 196. This clamping block or drag block canbe moved away from the strip thereby to permit removal of the strip orinsertion of a new strip into the applicator by means of a cam lever 197pivotally mounted on a control rod 198 which is secured as shown in FIG.1 to the clamping block.

The operation of the disclosed embodiment is best described withreference to the timing diagram, FIG. 13. During each operating cycle,the main drive slide is driven downwardly and is then retracted by thepiston rod 28. This piston rod may be controlled by any suitable valvesystem (not specifically shown) which is advantageously arranged torespond to movement of the conveyor on which the printed circuit boardsare carried past the inserting apparatus. The insertion slide 36 dwellsin its upper position during an initial portion of the cycle and ismoved downwardly with the main drive slide 20 after the lower surface ofthe clevis on the main drive slide moves against the upper end of theinsertion slide 36. The insertion slide and the main drive slide movedownwardly as a unit until the terminal held in the tip 88 of theinsertion slide has been inserted into the board and staked thereto byspreading of the staking members 194. During the upward stroke of themain drive slide 20, the insertion slide moves with the main drive slideuntil the stop pin 48 on the upper end of the insertion slide engagesthe fixed stop screw 50. The terminal severing blades 126, 128 are intheir closed positions at the beginning of the operating cycle and areopened during downward movement of the main drive slide by the leversand cams 150. These blades dwell in their opened positions while theterminal inserting operation is carried out and while the terminal stripis fed to locate the leading terminal of the strip immediately beneaththe severing blades. The severing blades are closed towards the end ofthe operating cycle, i.e., during the final portion of the upward strokeof the main drive slide, to sever the leading terminal of the strip andthey dwell in their closed positions during the final portion of thecycle. The strip feed pawl is in its retracted position (FIG. 3) at thebeginning of the cycle and dwells in this position until the feed slide168 is engaged by the setscrew 79 mounted on the clevis 30 of the maindrive slide. Feed pawl 160 is then moved downwardly during the finalportion of the downward stroke of the main drive slide to feed the stripand is retracted immediately thereafter as the main drive slide movesupwardly from its lowermost position. As indicated in the timingdiagram, feeding of the terminal strip is completed well before theleading terminal of the fed strip is severed by the severing blades 126,128. After this leading terminal has been severed from the strip, it isheld in the lower end of the insertion slide in preparation for the nextoperating cycle.

Changes in construction will occur to those skilled in the art andvarious apparently different modifications and embodiments may be madewithout departing from the scope of the invention. The matter set forthin the foregoing description and accompanying drawings is offered by wayof illustration only.

Iclaim:

1. Apparatus for inserting contact terminals into a printed circuitboard or the like, said terminals being in end-to-end strip form, saidapparatus comprising:

strip-feeding means for feeding said strip along a predetermined feedpath, said feed path terminating at a location above a printed circuitboard;

insertion slide means movable from said location towards and away fromsaid printed circuit board, said insertion slide means havingterminal-gripping means for carrying the leading terminal of said striptowards said printed circuit board;

a pair of cooperable severing members disposed on opposite sides of saidfeed path at said location, said severing members being movablerelatively towards each other, to shear said leading terminal from saidstrip, and then relatively away from each other to permit feeding ofsaid strip; and

actuating means effective to move said severing blades towards eachother during retractile movement of said insertion means during the endportion of one operating cycle and for moving said severing members awayfrom each other and for moving said insertion means towards said printedcircuit board during the next operating cycle.

2. Apparatus as set forth in claim 1 wherein said terminal grippingmeans comprises a pair of arms on said insertion slide means, one ofsaid arms being resiliently biased towards the other arm whereby saidleading terminal is resiliently gripped between said arms.

3. Apparatus as set forth in claim 1 wherein said actuating meanscomprises a reciprocable drive slide, said drive slide having a lostmotion coupling to said insertion slide means whereby movement of saidinsertion slide means towards said printed circuit board commences aftermovement of said drive slide, and camming means effective between saiddrive slide and said severing blades to move said severing blades awayfrom said strip prior to movement of said insertion slide means.

tion slide, said insertion drive slide being movable relative to saidinsertion slide in the event of complete insertion of said leadingterminal through said board prior to the end of the stroke of saidinsertion drive slide.

